JPH0663867U - Sealing structure for ignition device of internal combustion engine - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To improve the sealability without taking up space and to facilitate manufacturing. In a seal structure of an internal combustion engine ignition device, a plug insertion opening surrounded by an annular wall is sealed by an elastic rubber 26 fitted to a high-voltage wire connected to an ignition plug. A first seal portion 32 that comes into contact with the inner peripheral surface of the mouth and a brim-shaped second seal portion 34 that comes into contact with the open end surface of the plug insertion opening are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a seal structure for an internal combustion engine ignition device.

[0002]

[Prior art]

 The spark plug is attached to the cylinder head of the internal combustion engine, but in order to prevent water, dust, etc. from entering through the hole for inserting the spark plug, as shown in FIGS. 7 and 8, the high-voltage line 2 side connected to the spark plug 1 A rubber cover 3 is fitted on the plug and the plug insertion port 4 is sealed.

The rubber cover 3 is fitted to a hooking portion of an ignition coil 6 that is fastened to the main body 5 (cylinder head or the like) side, press-fits and supports the shield pipe 7 of the high-voltage wire 2, and also has a plug insertion port 4 A skirt portion 9 is provided which is in contact with the inner peripheral surface of the plug and covers the outer periphery of the opening end (annular wall) 8 of the plug insertion port 4 protruding from the surroundings (see JP-A-63-75358, etc.).

[0004]

[Problems to be solved by the device]

 However, in the case of a rubber cover having such a shape, the skirt portion 9 becomes an undercut, which complicates the manufacturing of the mold, and has many irregularities, so that the life of the mold is short.

Further, since the skirt portion 9 covers the outer circumference of the annular wall 8 of the plug insertion opening 4, a space is required and a predetermined space is required between the skirt portion 9 and the mounting boss 10 of the ignition coil 6. As a result, the ignition coil 6 and the main body 5 become large.

Further, since the sealing surface is only the inner peripheral surface of the plug insertion port 4, when water is accumulated in the annular wall 8 or more, there is a concern that water may enter the sealing surface.

The present invention aims to solve such a problem.

[0008]

[Means for Solving the Problems]

 This invention relates to a seal structure of an internal combustion engine ignition device in which a plug insertion opening surrounded by an annular wall is sealed by an elastic cover fitted to a high-voltage wire connected to an ignition plug. A first seal portion that contacts the inner peripheral surface of the insertion opening and a brim-shaped second seal portion that contacts the opening end surface of the plug insertion opening are provided.

[0009]

[Action]

 Therefore, it has a simple shape and can be sealed by the plurality of first and second seal portions, and the seal portion at the opening end face of the plug insertion port has a brim shape, so that the distance from the periphery can be reduced.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a plug insertion opening 21 provided in a main body 20 such as a cylinder head is surrounded by an annular wall 22 around the opening, and a hole 24 that is continuous with the inner peripheral surface 23 by a wall surface. A spark plug 25 is attached to the bottom of the.

The elastic rubber 26 that seals the plug insertion port 21 is fitted to the hooking portion 28 on the lower surface of the ignition coil 27, and the shield pipe 30 of the high voltage wire 29 from the ignition coil 27 is press-fitted and supported in the lower portion. .

When the shield pipe 30 is inserted into the plug insertion port 21, the elastic rubber 26 fits into the plug insertion port 21, the shield pipe 30 fits into the ignition plug 25, and the high voltage wire 29 comes into contact with the plug terminal 31. The elastic rubber 26 has a cylindrical first seal portion 32 that comes into contact with the inner peripheral surface 23 of the plug insertion opening 21 and a collar that comes into contact with the opening end surface (upper surface of the annular wall 22) 33 of the plug insertion opening 21. The second seal portion 34 having a shape of a circle is provided, and sealing is performed on a plurality of surfaces.

In this case, the plurality of annular protrusions 35 formed on the first seal portion 32 are brought into close contact with the inner peripheral surface 23 of the plug insertion opening 21.

Further, the ignition coil 27 is fixed to a mounting boss 36 formed on the main body 20 by a bolt 37, and in this set state, the second seal portion 34 has a predetermined surface pressure and has an opening end surface of the plug insertion port 21. 33 is contacted.

Reference numeral 38 is an air hole communicating with the inside of the hole 24.

As described above, the first seal portion 32 contacts the inner peripheral surface 23 of the plug insertion opening 21 and the second seal portion 34 contacts the opening end surface 33 of the plug insertion opening 21, thereby sealing the opening. Even if water is accumulated in the end annular wall 22 or more, the water does not enter the inner peripheral surface 23 side of the plug insertion port 21 and can reliably seal.

Further, since the seal portions 32 and 34 have a simple shape, the mold of the elastic rubber 26 is easily manufactured, and since the mold has few irregularities, the life of the mold is remarkably extended.

Further, since the seal portion 34 of the opening end surface 33 of the plug insertion opening 21 is a brim, the gap between the annular wall 22 at the opening end and the mounting boss 36 of the surrounding ignition coil 27 can be reduced. Therefore, the ignition coil 27 can be made small, and the body 20 can be made compact.

Since the seal portion 34 has a brim shape, even if the dimensions of the respective portions vary, it is possible to deal with the situation and ensure the seal.

3 to 6 show other embodiments, respectively.

In FIG. 3, the outer diameter of the flange-shaped second seal portion 41 of the elastic rubber 40 is made larger than the outermost diameter of the opening end surface 33 of the plug insertion port 21, that is, the annular wall 22.

According to this, water does not collect on the opening end surface 33 of the plug insertion port 21, and the sealing can be performed more reliably.

FIG. 4 shows that the thickness of the collar-shaped second seal portion 51 of the elastic rubber 50 is gradually reduced toward the outer periphery, and FIG. 5 is the plug insertion port of the collar-shaped second seal portion 61 of the elastic rubber 60. The entire portion of 21 that contacts the open end surface 33 is thinned.

With this configuration, even if the seal portions 51 and 61 are distorted during setting, the air holes 38 are not deformed by this and the air holes 38 can be prevented from being blocked. In FIG. 6, the cross section of the air hole 71 of the elastic rubber 70 is formed in an oval cross section that is long in the radial direction of the elastic rubber 70.

In this way, even if the seal portion 72 or the like is distorted at the time of setting and the air hole 71 is deformed, the air hole 71 is not blocked.

[0027]

[Effect of device]

 As described above, according to the invention, in the seal structure of the internal combustion engine ignition device, the plug insertion opening surrounded by the annular wall is sealed by the elastic cover fitted to the high-voltage wire connected to the ignition plug. Since the cover is provided with the first seal portion that comes into contact with the inner peripheral surface of the plug insertion opening and the brim-shaped second seal portion that comes into contact with the opening end surface of the plug insertion opening, a reliable seal can be obtained and an elastic rubber can be used. Since it is easy to manufacture and the space around the plug insertion port can be made small, the ignition coil etc. can be made compact.

[Brief description of drawings]

FIG. 1 is a sectional view.

FIG. 2 is a perspective view in which a part of elastic rubber is cut away.

FIG. 3 is a cross-sectional view of main parts of another embodiment.

FIG. 5 is a cross-sectional view of main parts of another embodiment.

FIG. 6 is a plan view of an essential part of another embodiment.

FIG. 7 is a sectional view of a conventional example.

FIG. 8 is a perspective view in which a part of a conventional elastic rubber is cut away.

[Explanation of symbols]

 21 Plug Insertion Port 22 Annular Wall 23 Inner Circumferential Surface 25 Spark Plug 26 Elastic Rubber 27 Ignition Coil 29 High Voltage Wire 30 Shield Pipe 32 First Seal Part 33 Open End Face 34 Second Seal Part 38 Air Hole 41 Second Seal Part 51 Second Seal Part 61 Second Seal Part 71 Air Vent

[Procedure amendment]

[Submission date] February 10, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a sectional view.

FIG. 2 is a perspective view in which a part of elastic rubber is cut away.

FIG. 3 is a cross-sectional view of main parts of another embodiment.

FIG. 4 is a cross-sectional view of a main part of another embodiment.

FIG. 5 is a cross-sectional view of main parts of another embodiment.

FIG. 6 is a plan view of an essential part of another embodiment.

FIG. 7 is a sectional view of a conventional example.

FIG. 8 is a perspective view in which a part of a conventional elastic rubber is cut away.

[Explanation of Codes] 21 Plug Insertion Port 22 Annular Wall 23 Inner Circumferential Surface 25 Spark Plug 26 Elastic Rubber 27 Ignition Coil 29 High Voltage Wire 30 Shield Pipe 32 First Seal Part 33 Open End Face 34 Second Seal Part 38 Air Hole 41 Second seal portion 51 Second seal portion 61 Second seal portion 71 Air hole

Claims (1)

[Scope of utility model registration request] 1. A seal structure of an ignition device for an internal combustion engine, wherein a plug insertion opening surrounded by an annular wall is sealed by an elastic cover fitted to a high-voltage wire connected to an ignition plug. A seal structure for an ignition device of an internal combustion engine, comprising: a first seal portion that comes into contact with an inner peripheral surface of a mouth; and a flange-shaped second seal portion that comes into contact with an opening end surface of a plug insertion opening.